Process of separating pulp fibers from pigments, size, filling and other impurities.



B. W. PETSOHE.

PROGESS 0F SEPARATING PULP FIBERS FROM PIGMENTS, SIZE, FILLING, AND OTHER IMPURITIES.

APPLICATION FILED MAY 7, 1909. 955,898. Patented Apr. 26, 1910. 3 BHEETB-SHEET 1.

-B. W. PETSGHB. PROCESS OF SEPARATING PULP FIBERS FROM PIGMENTS, SIZE, FILLING, AND OTHER IMPURITIBS.

APPLIUATION FILED MAY 7, 1909.

3 SHEETS-SHEET 2.

flaw/v Patented Apr. 26, 1910.

ZQiZi Z vwa M507 V- 5 14 witness 0:

B. W. PETSCHE. rnoonss or SEPARATING PULP FIBERS mom PIGMENTS, SIZE, FILLING, AND OTHER IMPUBITIES.

APPLICATION FILED MAY7,1909. I 955,898, Patented Apr. 26, 1910.

' UNITED STATES PATENT OFFICE.

BISMARCK WILLIAM PETSCHE, 0F YONKERS, NEW YORK.

PROCESS OF SEPARATING PULP FIBERS FROM PIGMEN'TS, SIZE, FILLING, AND OTHER IMPURITIES.

Specification of Letters Patent.

Patented Apr. 26, 1910.

Application filed May 7, 1909. Serial No. 494,711.

My invention relates to process and apparatus for recovering pulp from waste paper, such as newspapers, books and the like, and consists of the hereinafter described process and apparatus for separating the pulp fibers from t e i urities, particularly printers ink, size and e like, adhering to such fibers as the result of the previous use of such waste papers, from which the pulp fibers were recovered.

In carrying on m improved process, the waste paper is first isintegrated 1n the usual way in a beater engine, the pulped mass is then conveyed to a chest, where an alkaline solution is added thereto, and thoroughly mixed and agitated by a mechanical agitator, for a time suflicient to reduce the adhesive capacity of the oil of the ink and of such size and filler, as may not have been sufficiently softened or dissolved in the beating process, to the extent necessary for separating these impurities from the fibers of the pulp.

The alkaline solution may be prepared by dissolving one part of caustic soda in one thousand parts of water, measured b.

Weight. Such solution will be found su cient for dissolving the cohesity of the sub stances and also their adhesity to the fibers of pulp recovered from ordinary print papers, newspapers, books and the like, though some other papers, particularly such having printed thereon pictures, large size type, or some other particularly sized papers, might require a somewhat stronger alkaline solution. In this, however, care must be taken; it is preferable to use a weaker solution and work the material for a longer time in 'the'chest, orto einplo hot alkaline solution, which is more e ective to solve or liquefy the dried ink, size, etc.,'than to use a stronger alkaline solution or other more intense .lsolvents. Caustic soda is eflicient for. all papers, though other alkali may be used to prepare the solution. .The alkaline solution may be used in the heaters in place of the water required for the beating process, it is, however, referable to beat the stock in ordinary so t water and then soak and work it in the alkaline solution in the the material from which the pulp is to be recovered, whether hot or cold solution is used, and to some extent also upon the stren th of the alkaline solution em loyed. It is est determined by taking a sma l sample of the mass, and then shaking it in clear warm water in a glass. This test will show, whether the fibers of the ulp are freed from coagulated oil, the size, Her and other impurities.

Next the se arating of the pulp fibers from the particles of ink pigments and the insoluble ingredients of the size is undertaken. This part most clearly distinguishes my improved process from other processes, having the same purpose, as heretofore were known or employed in the art. These prooesscs proceeded upon the theory thatv these impurities may be removed by filtration or by floating them up and carrying them away by overflo\vit being assumed that the specific gravity of the pulp fibers is greater than that of the carbon of the ink and other impurities, and consequently, that the former will settle on the bottom of the vessel, and the latter be carried away with the flow. Therefore, to my best knowledge and belief, no one has yet succeeded to recover really clean pulp and no one has yet succeeded to carry on any of the processes in a com mercially economical way. In my improved process the pulp fibers are separated from the residue of the ink, size and filler by screening, the operation being performed by streams of water acting upon the pulped mass to pass it over the screens, the 1mpurities being driven through the meshes .and the purified fibers conveyed to a recepressing out the solution gitudinal sectional view of the apparatus. Fig. 3 a perspective view of the upper trough, the (coarse) screen and gutter; and Fig. 4 a similar viewof the lower trough, the separating (finer) screen and of the series of sprinklers arranged in connection therewith.

The apparatus consists of the troughs A, B, C; tank D screens E and F and sprinklers G and H, arranged substantially as shown in the drawings. Instead of arranging each of the two screens E and F over one of the two adjoining troughs, they may be both located in one trough, one above the other. In such an arrangement the coarse (18 to 24 meshes to an inch) .screen E would be on top and the fine (about 50 meshes to an inch) screen F underneath, the sprinklers G abovethe screen E, and the sprinklers H right underneath above the fine screen F. For such an arrangement the screen troughs would have to be made correspondingly deeper to accommodate both screens and'sprinklers. It is, however, much more convenient to, and a more satisfactory result is obtained from, the working of the apparatus, if arranged as shown in the drawings.

The details of the construction of this apparatus and the actions of the several parts will be well understood from the following description of its use in the process:

The pulped mass is discharged from the chest into the trough A, from where it flows or slides upon the coarse screen E and is propelled over it by the water discharged upon it an an angle of from 30 to from the nozzles a of the sprinklers G. Screen E is employed to exclude from the pulped mass such coarse parts of stock that might not have been sufiiciently pulped, andwhatever foreign coarse substances might have been contained in the stock. These coarse parts and impurities are driven into the gutter e and flow into the tank D; whereas the finely pulped mass passes through the coarse screen E into the trough B, and is then conveyed, in a rather rapid flow, upon the screen F. The streagns of water ejected upon th1s screen from the nozzles b of sprinklers H at an angle of about 30 to 45 to its plane, propel and roll over the pulped marial over the screen F all particles of ink,

pigment, size, etc., are separated from the fibers of the pulp and also the pulp. fibers are so arated from each other. The particles o ink, pigment, size, etc., fall, or are driven by the water, falling upon the screen from sprinklers H, through the meshes of the screen-F into trough 0, whose bottom slopes in a direction opposite to that of the screen F. By this trough the impurities and a large proportion of the water flow through the opening 0 into the tank D, where the impurities, removed from the pulp fibers, settle. The overflow d from tank D carries away what coarse particles or impurities float on the water in the tank D,and the sediment is discharged, from time to time, through the bottom outlet f. The clarified water, remaining in the tank, may be used over again for the beating engines.

The treatment of the pulped material for the recovery of the pulpfibers by this proc ess requires from three to five times its weight of water, but more than two-thirds of the water used may again be recovered for use in the beating engines. The quantity of cleaned pulp, recovered in this process is hardly any less in proportion, to the quantity of the waste materlal pulped in the beater than what is obtained in the ordinary pulping proeess, and the costs of the process are only a small fraction over and above the costs of the ordinary pulping process of such materials. The ulp recovered 'by this process requires no b caching, being as clean and white as it was originally, and while it is as suitable for manufacture of paper as fresh sulfite pulp, it is particularly suitable for manufacture of pulp boards for wat lining of chip and straw. boards, and for manufacture of combination boards and of coated boards of all kinds.

I claim as my invention 1. The process of separating pulp fibers from pigments, size, filling and other impurities by passing the pulped material over a screen and subjecting it to the action of streams of water, directed thereon to move 1t over the screen.

2. The process .of separating pulp fibers from pigments, size, filling and other impurities bypassing the pulped material over a screen and subjecting it 'to the action of streams of water during its passage over the screen, substantially as herein set forth.

3. The process, of recovering pulpl from waste paper, newspapers, books and like, consisting of the following steps: 1, pulping and waste papers; 2, soaking the pulped material in an alkaline solution and simultaneously subjecting it to the action of a mechanical agitator; 3, driving the pulped material over a coarse screen by streams of water acting thereon; 4;, floating the material, passed through the coarse screen onto a fine screen and 5, subjecting it to the action of streams of water, directed thereon to move it over the screen.

BISMARCK wummriirstar. Witnesses WM. SHERMAN, GUY H. PEARSON. 

